Posted
by
samzenpuson Friday August 24, 2012 @06:27AM
from the old-copies dept.

ananyo writes "In the 1930s, the pioneering geneticist J. B. S. Haldane noticed a peculiar inheritance pattern in families with long histories of haemophilia. The faulty mutation responsible for the blood-clotting disorder tended to arise on the X chromosomes that fathers passed to their daughters, rather than on those that mothers passed down. Haldane subsequently proposed that children inherit more mutations from their fathers than their mothers, although he acknowledged that 'it is difficult to see how this could be proved or disproved for many years to come.' That year has finally arrived: whole-genome sequencing of dozens of Icelandic families has at last provided the evidence that eluded Haldane. Moreover, the study, published in Nature, finds that the age at which a father sires children determines how many mutations those offspring inherit. By starting families in their thirties, forties and beyond, men could be increasing the chances that their children will develop autism, schizophrenia and other diseases often linked to new mutations (abstract)."

If you are still able to have children at such an old age you have the luxury of passing mutations to children. Think of your first ones fathered at a young age as survival of the species and the ones as you are older as way of branching out.
This plays out with the order children.. typically the eldest are more responsible and the younger ones more reckless and exploratory.

Yeah, it's old news to me that the age of the father matters but what I know since earlier is that the telomere count increased in male sex cells and that those was inherited by the offspring which in return might get a chance in living longer.

Or you could argue that maybe not because they got worse protection against cancer.

But seriously. It make sense in an evolutionary way now when I think about it:

If the father has managed to live for long there's a chance his genes are better than a father not as old,

Right now though, surviving doesn't mean much in terms of quality of life or of beneficial mutations. We can keep sick and diseased people alive for longer, we fix ugly people with braces and plastic surgery, etc.. selection pressures are changing in our society, and it's difficult to think of the change of direction as a good one for the future generations. At least we are coming to understand genetics better, and therefore may be able to sort out some of these issues anyway..

You're saying that for example people with diabetes or other special dietary requirements don't regularly have offspring? There are lots of life threatening problems that aren't visible or socially stigmatic these days.

True, but at least one of your choices is a poor one. Type II diabetes, the most common one these days, is primarily due to dietary causes, not genetic ones. As for special dietary requirements, celiac/gluten free has a genetic component but many others are suspected to be environmentally caused.

As i understand the issue, a mutation that would have been deadly in the past can now sometimes be "fixed" in some way or another, and the defective gene is thus allowed to spread. I get why this is bad if suddenly society collapses and the treatment is no longer available, or at least bad for the carriers of that particular gene.
But in the case where the world goes on and the treatment remains available, wouldn't the defective genes offer new combinations to make new mutations from that won't all be bad?

I wouldn't tie in intelligence intrinsically with wages, but I suppose there must be some kind of correlation in general. To make the really big bucks though, I think you have to be more sociopathic than intelligent!

I read the studies and this really isn't that big a deal. For instance, the chance of autism is increased by 20-30% but there is still only a 2% chance of actually having autism appear. So, effectively there is a 0.6% (at most) additional chance that autism will develop in a child whose father is over 40. Autism is an especially hot topic right now due to the increase in proper diagnosis and therefore the increase in documented cases over recent years. This isn't due to more new babies being born with autism, but that they are better at diagnosing it and not thinking it's something else. The chances are still more-or-less the same.

Your numbers suggest about 30% (at most) of new diagnoses as being from older fathers, that's not insignificant. Yea the probability is still small in general, but within the autistic community it's relevant.

Absolutely. We need to encourage our children to have children at about 16, and and have us raise them. Then, when they are 32, and actually ready to raise children, they can have their children do the same.

I just need to jerk off and store my sperm in the freezer at the age of 20?
But then isn't mutation the key to natural evolution?

In part. Genetic drift is as important as mutation, if not more, and at least it does not lead to damaged offsprings. You probably don't need that many mutations to keep evolution going. (And there are other mechanisms causing genetic diversity as well.)

It meshes with the theory that women choose older men as partners because they are in a better position to care for offspring, but will try to have affairs with younger, sexier men. A man's sperm is separate from his ability to care for a child I suppose.

Cue hundreds of slashdot commenters with some vein of "She's been cheating on me with the gardener I just KNOW it!"

Well there is research that shows that women are attracted to different men when they're ovulating than they are when they're not. Link here [discovery.com]

Oh I'm not really a believer in evo-psych at all I just thought this discovery bolstered one of it's theories. I agree with what you said about social constructs. But I'm pretty sure the evo-psych people have a point about attraction being influenced by hormones, etc.

But seriously, who thought that leaving something like fathering a child would lead to fewer or the same number of mutations? Everybody who's everybody knows age and telomere shortening leads to a higher rate of mutation... That's why if we didn't otherwise get killed, wear out or otherwise malfunction, we'd eventually die from all the cancer.

Well I'm surprised about the father/mother relation. It was my understanding that birth defects increase dramatically with the age of the mother, and less so with the age of the father. Birth defect does not necessarily mean mutation, but this result still surprises me.

Mutations are what provide "fuel" for evolutionary innovation. Sure, they more often cause problems than "good", but without mutations fish would never walk on land, apes would never step down from trees, and that mole on the back of my neck would never grow an eye, allowing me to see people sneaking up on me in basketball.

Okay, I made up the last one, but the point is that mutations are a trade-off, and perhaps necessary for the long-term survival of humanity. The problems an individual faces by being natu

hmm, your summery about the eggs does not make sense. According to this arcticle:-Women must choose younger biological fathers.-The health risk are not as much a problem of the eggs, but mainly in the pregnancy.

Also i do not like the summary about autism, schizophrenia in such articles. Autism is not a disease where you have it or not have it, it is a spectrum, where the intelligent ligher cases might never be diagnosed with autism, and the heavy case might always be there.

Although women's sex drive (supposedly) increase through late 30's, fertility does not. All that worry in your 20's about your girlfriend getting pregnant turn into worries in your 30's that your wife won't get pregnant.

By your thirties you should be wise enough to know that a low stress lifestyle is the key to happiness. Children are stressful, and accordingly parents are consistently less happy than non-parents, despite their assertions to the contrary.

Children are stressful, and accordingly parents are consistently less happy than non-parents, despite their assertions to the contrary.

If you're infertile, or if you lost custody in the divorce, and this is your rationalization to help you stay sane, then stop reading at this paragraph. You're absolutely right. Children are nothing but stress and heartache, and you should pity us as you jet off to your vacation in Europe, made affordable by the fact that you never had to buy any diapers. Children are nothing but heartache.

If you've chosen never to have children because you don't want the responsibility, then stop reading at this paragraph.

Apples and oranges. You should compare sperm production to egg viability. Egg viability is best in young women. And as for women somehow sexually peaking in their late thirties, all that deserves is a big belly laugh. Every man knows different.

Sexually speaking, guys peak at age 17, producing the most sperm. Women peak at 37.

A woman trying to have children at 32 years of age or older is monstrously more likely to have complications.Late teens to early twenties is when both men and women are at their sexual peak.

What you're talking about is the phenomena of middle-aged women getting desperate as they age and their clock ticks out, so they go on a 2 year stint of pounding the mound in every way imaginable as if they were fulfilling some sort of sexual bucket list.

The testes are towards the outside of the body and vulnerable to all sorts of things, while the ovaries are better protected. Furthermore, sperm is produced over the course of a lifetime, whereas eggs aren't. The end result is that eggs are likely to have the original genetic material of Mom, while the sperm is more likely to have been modified (by radiation, damage from trauma, copying errors, etc) from the original genetic material of Dad.

This seems like a good evolutionary strategy, however it arose: Mom provides a version that has allowed her to survive and reproduce, suggesting a minimum viability, which she passes on to the child. Dad provides a version of an evolutionarily successful human that is modified, allowing the species to improve itself (And if he's lived to old age, he was probably an effective survivor evolutionarily speaking).

Except: A woman is born with all the eggs she will ever have (they are not produced over the woman's lifetime). On the other hand sperm are produced more on an as-needed basis. So, there is much more opportunity for problems to arise with eggs (presumably why the chance of having a Down's Syndrome child increases with the mother's age).

So the finding of ovarian stem cells in women of reproductive age isn't a possible mechanism? Given they also made the discovery in mice and where able to successfully create eggs and fertilize them with the mice?

I'm not saying either is right, but to prove it isn't you have to have evidence.

It would be fairly easy to look for those stem cells and humans and find out if they're turning into ovums. They're not there.Mice aren't people. Humans breed at a rough maximum of 1 per year for 30 years. Mice pump out offspring like, well, mice. Menopause isn't an exhaustion of supply - there are enough eggs in one human ovary to last a hundred lifetimes. We already can delay and reverse menopause, just as we can with andropause. The side effects (basically CANCER OUT THE ASS) are not worth it. We

Except: A woman is born with all the eggs she will ever have (they are not produced over the woman's lifetime). On the other hand sperm are produced more on an as-needed basis. So, there is much more opportunity for problems to arise with eggs (presumably why the chance of having a Down's Syndrome child increases with the mother's age).

Correct. Older eggs suffer far more damage than older sperm. It was commonly thought for many, many years that sperm age had no consequence. It was proven 5 or 6 years ago that it absolutely does. Then, right on queue, Slashdot has a story about it.

The testes are towards the outside of the body and vulnerable to all sorts of things, while the ovaries are better protected

Which doesn't have anything to do with genetic damage to the cells within. We already knew that older mothers are more susceptable to passing on genetic mutation as they age, all this research is showing is that men's DNA gets damaged too. Previously we blamed the genetic damage passed on by mothers to the fact that eggs are created in a woman's body before puberty, and slowly releas

Absolutely, I just like it when an experimental result matches educated guesses.

Reminds me of my joke about good research: A farmer noticed that his brown horses collectively were eating twice as much as his white horses collectively. After properly researching the subject, he decided to focus on the fact that he had 20 brown horses and only 10 white horses.

men could be more mature (no need to get in a divorce situation due to a driving urge to mount some other female) and be earning more money, thereby ensuring a more stable and financially sound basis for their household.

that the chance the kid might come out with biological issues is a slight increase. while a younger father has a significantly increased chance to still feel a need to sow the wild oats and not be earning a lot

not that older men can't be broke, and not that older men can't still cheat. but it helps to have all your sexual adventures when you are in your 20s, and not feel the need to do that when you are older. additionally, marrying older means the woman is more mature too, and you are more mature, and so the chance of your marriage lasting is greater because you understand the value of commitment over impulses, you are more interested in settling down, and you can pick the right spouse based on more ephemeral mature qualities rather than the mistakes you can easily make in your 20s and then feel like leaving the person later. all of this is of course better for kids: a stable home of mature parents who earn more money

in other words, this news is a big shrug: "so what." the beneficial factors for having kids in your thirties and forties vastly outweigh the slight genetic risks

I was 40 when my son was born, and I can't keep up with the little mutant (though I hear of a special school for kids like him out in Westchester County, NY). There's a reason people have kids in their 20's, it's a physically exhausting challenge.

But yeah, the mature relationship with my wife and stable financial situation are nice. Though I do wish I could stay awake past 8:30 PM.

Well no, not if it's your wife who has to get up at 3:00 AM to feed the baby. But most modern men are a lot better than that. You can say with a straight face that you can get up in the middle of the night and still be productive at work? I did it at 35 and it was hell.

Seems more like the process of "maturation" is suspended as men become confirmed bachelors and women become confirmed sluts. Compare your grandparents who married at 20 and the current generation who are more likely to have autistic bastards than settle down and tell me who is more of an "adult".

I got a son with a "de novo" mutation (proven by DNA-sequencing of the MLL2 gene) and although the chance of getting such a child is small, the impact is very big. Luckily, I live in a country where lots of support is available and I did not go broke financially, but still the impact it had on our family is quite big. Although he is almost 15, he needs supervision like a 6 year old. Luckily, my marriage did not break-up, but I know that it happens frequently. Especially, for my daughter, this was a big burd

Well, it has been known that older men will father more daughters than sons because the male embryos are more delicate and more prone to be rejected by the mother's body than female embryos. A case in point, Tony Randall fathered a daughter at age 76 and another at age 77. It's never too late.

I do not doubt the research that shows that older men pass on more mutations, but is it that simple? Do these older men also have older wives/partners? If so, is it strictly that the sperm of older men is more susceptible to mutation or are the eggs of older women less discriminate and more likely to allow a defective sperm to penetrate and fertilize the egg? In other words, would these mutant sperm been able to fertilize a younger healthier egg?

The article is rather neutral, but the premise is being misinterpreted. This is comparing the genetic mutations of older fathers, not the genetic mutations of older men relative to their younger days. A man more susceptible to mild genetic abnormalities may be a late bloomer who takes years longer to be comfortable in social and family settings, resulting in him becoming a father later. If a slightly odd duck doesn't manage social situations well until they are later in life, doesn't this mean older fa

I was 35 when I conceived my son. He was diagnosed with a 'de novo' (new) mutation in one of the two copies of his MLL2 gene: a single base pair was deleted at position 2272 ("c.2272delG"). This causes half of his MLL2 proteins to be not working resulting in Kabuki Syndrome. He has an academic IQ of around 50, but with some tasks he out smarts everyone I know: he can instantly see who are missing from a certain setting. Saw him walk into his class room, look around, walk to his teacher and when asked by her who were missing, mention the names without hesitating (or looking around) for a second.

Don't worry. I saw this guy [slashdot.org] volunteer to pay for the downside since the risk is so small [slashdot.org]. Shoot him an email and ask him when the check is going to arrive in the mail. If he doesn't pay up, maybe you could just shoot him.

I believe this has been a gaining trend for at least several hundred years in the West, and indeed, likely throughout most societies for most of history: older, dominant males gets the younger, more valuable females.

It'd be hard to do a study on birth defects over time, considering the time scale we're dealing with here. I suspect that mutations are historically more common in the races which adopted a hierarchical sexual pecking order early on.

So, it turns out that Nature is gender neutral. Old mothers have increased risk of passing congenital diseases to their offspring, no we know it's the same for the fathers. I'd say that's not very unexpected, although it's good to have some evidence for that -- this study is a step in the right direction.

I live in a very upscale and rather posh part of California. There is an abnormally high rate of children born with disabilities including M.S. and Down Syndrome. The one obvious correlation is the shockingly obvious tie between the age of the fathers and the children with disabilities. As is the case with many upscale neighborhoods, there is a significant number of men in their 50s and 60s fathering children with women in their late 20s and early 30s.

Well, that might explain why the kids of most of the people I've met who waited until their 40s and 50s to have children are all retarded or otherwise 'a bit touched'. But I don't suppose being a spoiled only child helps matters much.